WashPost: The threat of carbon emissions on the world’s oceans

The harrowing history is recorded in mud samples millions of years old, taken from the sea floor near Antarctica: It reveals a mass extinction of single-celled organisms that no doubt caromed far up the food chain. A similar effect today could kill off coral, plankton and mollusks, constricting the diets of a range of fauna that rely on them, including salmon — and humans.

Assuming similar results now, ocean acidification’s most extreme possible effects might not occur for many years. Yet today’s rate of acidification is 10 times that of the most comparable surge in atmospheric carbon in the last 300 million years, Barbel Honisch, a scientist involved in the study, tentatively estimates.

Scientists cannot and need not be definitive about exactly what will happen and when all over the earth. As ever with climate change, there is a range of risks involving mind-bogglingly complex planetary systems that scientists can attempt to anticipate, and probably many they have not considered. The point is there are enough dangers of such magnitude and probability that humans should invest in reasonable policies to avoid them…